Public understanding of vaccines Flashcards
Public understanding of vaccines
Most scientists think about risk in terms of populations and most patients will think about risk to themselves/child. For herd immunity to be achieved, risk must be thought of in terms of the population. The source and presentation of data has a huge impact on how risk is perceived.
Absolute risk is the size of your own risk. Absolute risk reduction is the number of percentage points your own risk goes down if you do something protective. Relative risk is the number that tells you how much something can change your risk, and can be expressed as a % increase or decrease.
Andrew Wakefield
was a British gastroenterologist who believed he had discovered the cause of Autism in 1998 – the MMR vaccine. His claim was that 8 children developed autism within 1 month of MMR. They had GI symptoms of intestinal inflammation, which he believed led to translocation of usually impermeable peptides to the bloodstream, then to the brain where they affected development. His study was limited because it used a small, biased sample. GI symptoms did not predate autism in several children, which is inconsistent with the notion that intestinal inflammation facilitated bloodstream invasion of encephalopathic peptides. No encephalopathic peptides have ever been identified between GI and brain.Media coverage picked up the story which influenced public opinion. The government had to respond to it (saying it was safe). However, government responses are limited when the public trust is low (26% of trust in 2017). This is the Muckraker model above (right).
MMR vaccine options/ alternatives
- *
Vaccinate – the correct thing to do.
Delay vaccination – increased risk of MMR Use single vaccinations
o Separate vaccines for measles, mumps and rubella are unlicensed in Britain, but it is not illegal to import the vaccines as long as they inform the Medicines Control Agency (MCA) that they are bringing the vaccine into the country
o Single vaccinations must be done privately, at £45. Homeopathic vaccines
o A nosode is a homeopathic remedy prepared from a pathological specimen. The specimen is taken from a diseased animal or person and may consist of saliva, pus, urine, blood, or diseased tissue. The material is sterilised until no bacteria is present and then sold as pellets
Don’t vaccinate – increased risk of MMR
Role of the pharmacist:
- To increase awareness about the importance of vaccinations
- Identify those patients who may benefit from specific vaccinations
- Help patients to make informed decisions about vaccinations
If 95% of the population is vaccinated, most childhood diseases could be eliminated.
Global perspectives
Mortality rates for children < 5 declined in all regions of the world between 1990 and 2012, however deaths (per 1000) in Sub- Saharan Africa and South-East Asia were high. This may be attributed to the growing population and development status.
Pneumonia – 14%
Diarrhoea – 10%
Malaria – 7%
In Sub-Saharan Africa,
malaria is the biggest cause of death. There is now a vaccine available for malaria.
In low/middle-income countries (South-East Asia)
diarrhoea & pneumonia are the biggest causes of death. It is worth noting that 74% of pneumonia & diarrhoea deaths in 0-4-year-olds occurred in only 15 countries.
Streptococcus pneumoniae
is responsible for 33% of pneumonia deaths. It is a gram positive, encapsulated diplococcus, with > 90 known serotypes. It is transmitted via droplets (coughing, sneezing) and causes pneumococcal pneumonia, meningitis, sepsis, otitis media & sinusitis. It is exacerbated by crowding, indoor air pollution, tobacco smoke, immunosuppression, lack of exclusive breastfeeding. There is increasing resistance to penicillins and other antibiotics. The Prevenar 13 vaccine is available as 3 doses, given 4 weeks apart from 8 weeks of age. 30 countries have introduced the PCV vaccine since 2010, causing a 25-30% reduction in cases, with 30% of children worldwide vaccinated.
Haemophilus influenzae
is responsible for 16% of pneumonia deaths. It is a small, gram negative bacterium with several serotypes, based on capsular polysaccharides; type b (Hib) is the most virulent. It is transmitted via droplets (coughing, sneezing) and causes pneumonia, bacteraemia, cellulitis, meningitis, septic arthritis. The Infanrix hexa & Menitorix gives protection against Hib. It has reduced cases of pneumonia by ~20% with 60% of children worldwide having been vaccinated for Hib.
Rotavirus
is responsible for 27% of diarrhoea deaths. There are (at least) 28 strains that commonly infect infants and under 5s via faecal-oral transmission. The symptoms last 3-8 days and include severe watery diarrhoea, severe vomiting, fever and abdominal pain, loss of appetite & dehydration. The Rotarix vaccine is available as 2 doses give 4 weeks apart from 8 weeks of age. Rotavirus vaccination has been introduced in 19 countries and has caused a drastic reduction in the number of severe rotavirus cases by 74%.
Immunisation saves
2 to 3 million deaths every year from diphtheria, tetanus, pertussis and measles. However, the proportion of the world’s children who receive recommended vaccines has remained steady for the past few years. In 2013, an estimated 21.8 million infants worldwide were not reached with routine immunization services, of whom nearly half live in 3 countries (India, Nigeria and Pakistan).
Barriers for immunisation include war
(thereby affecting imports and health-care), terrorism, fear of side effects, and a poorly established healthcare system. Ensuring that quality infrastructure (legislation, regulation, health care system, finance, human resources) is in place increases immunisation rates.
Removing these barriers will require action by many different stakeholders, including
governments, NGOs & pharmaceutical companies. The following are potential solutions for closing the immunisation gap:
* Free/ affordable access to vaccines
* Education programmes to ensure there is understanding of the importance of vaccine
* Implement ceasefires in war-stricken countries
* Manufacture locally, where possible (more affordable).
